In the past, when a customer was delinquent in the payment of telephone call charges, the local telephone company would commonly disconnect the customer's line or not provide the customer with dial tone until the delinquent charges were paid.
With only one long distance interconnect carrier serving the customers of a local telephone company, the local company would record and bill their customers for long distance as well as local telephone call charges.
With more than one long distance interconnect carrier serving local company customers, the new interconnect carriers recorded and billed long distance calls by requiring their customers to dial at least two telephone numbers, one to reach their long distance network, and the other to reach the called customer. In addition, the calling customer was also required to dial a personal identification number when connected to the interconnect carrier network. This number is used to verify that the caller was authorized to use the interconnect carrier's services and to charge for the call.
Calling customer identification and billing is typically performed by the new interconnect carriers only in a limited geographic area incorporating specific routes. Customers may also subscribe to make calls when they are outside the local geographic area of the interconnect carrier. However, a customer must first make an AT&T "800" service call to reach the new interconnect carrier, and then dial the telephone number of the called line followed by their own telephone number and personal identification number. This involves two interconnect carrier calls plus dialing the calling customer's telephone and personal identification numbers.
Recently, the Bell System local telephone operating companies were separated from AT&T which provides long distance interconnect carrier service. In addition, all local telephone companies were required to give their customers equal access to all interconnect carriers. That is, each interconnect carrier can be accessed by dialing the same number of digits. The local telephone company can still disconnect a customer's line for the delinquent payment of local telephone call charges. However, not all government regulators allow the local telephone companies nor do the local telephone companies desire to disconnect a customer's line for the delinquent payment of long distance interconnect carrier charges, particularly when the payment of local telephone call charges is not delinquent.
As a result, the interconnect carriers face the problem of how to deny long distance service or disallow the extension of a long distance call through their network when the calling customer is delinquent in the payment of long distance telephone call charges.